to george w. bush for homeland security and counterterrorism. also joining us, cnn analyst juliette kayyem who is a former assistant secretary for both u.s. homeland security and interestingly enough, a massachusetts homeland security adviser, as well. i want to start with juliette because we have some really is interesting information. new news about some developments going on at the airport right at this second. >> so, there's clearly going to be eyewitnesses. so what the police are doing is that they're starting to ask people at the airport to check their iphones. which is really smart. people don't know that they were witnesses. that they might actually have evidence in their phones or in their cameras. and so there's now sort of this search amongst all the people that were there, the tens of thousands of people, to say hey, did you see something? because the chances are, if the site was secure the last 48 hours, which it is because i used to do boston marathon security, someone probably got in in sort of chaos at the finish line. chaos is the wrong word. it's just more open than not.